Apparatus and method for forwarding data on multiple label-switched data paths
An apparatus and method for forwarding data on a network are described. A label-switching subnetwork within the network includes an ingress node and an egress node coupled to source and destination nodes, respectively, on the network. The ingress node sends a signal along a route within the subnetwork through a plurality of subnetwork nodes to the egress node. In response, the subnetwork nodes transmit response signals back along the route toward the ingress node which define the route through the subnetwork and simultaneously allocate a plurality of paths within the route. A single path can be selected for forwarding of data packets associated with a source/destination pair, ensuring that data packets arriving at the destination are not misaligned.
1. In a data-packet network, a method for routing packets through while ensuring load balancing and in-order delivery for unique packet flow defined by unique source/destination pairs, comprising the steps of:
(a) providing a label-switching sub-network having one ingress node and one egress node and at least two nodes internal to the sub-network for routing packets;
(b) creating a sufficient number of label-switched paths (LSPs) from the ingress node to the egress node such that each packet flow has a unique LSP; and
(c) associating each packet flow with one of the created LSPs;
wherein each sub-network node is connected by one or more physical parallel links and the number of LSPs created is equal to the least-common multiple of the number of links between each individual internal sub-network node in the node path, wherein the number of links between the sub-network nodes may differentiate and the sufficient number of LSPs are created based on a requirement to balance the distribution of LSPs over the physical links and each LSP created is utilized by the sub-network to balance the load of packet flow through the network.
2. The method of claim 1 wherein, in step (b) a mask value is added to a label value in the process of setting up the LSPs, and the LSPs are all created in response to a single signal sent from the ingress node.
3. A routing system in a data-packet network comprising:
a label-switching sub-network with one ingress node and one egress node, with at least two nodes internal to the sub-network, each node connected by one or more physical parallel links;
a mechanism for creating a sufficient number of label-switched paths (LSPs) from the ingress node to the egress node such that each packet flow has a unique LSP; and
a mechanism for associating each packet flow with one of the created LSPs;
characterized in that the number of LSPs created is equal to the least-common multiple of the number of links between each individual internal sub-network node in the node path, wherein the number of physical links between the sub-network nodes may differentiate and the sufficient number of LSPs are created based on a requirement to balance the distribution of LSPs over the physical links and each LSP created is utilized by the sub-network to balance the load of packet flow through the network.